AB0148 COULD THE RENIN-ANGIOTENSIN SYSTEM AFFECT THE PROGNOSIS OF GIANT CELL ARTERITIS? SINGLE-CENTRE RETROSPECTIVE OBSERVATIONAL STUDY
Authors: R. Venkateswaran, K. Gour, L. Sorensen, C. Harden, S. S. Zhao, A. Morgan, S. Mackie
Journal: Annals of the Rheumatic Diseases (2022)

Background About half of patients with giant cell arteritis (GCA) relapse while tapering glucocorticoid therapy 1 . A previous observational study reported that blockade of the renin-angiotensin system, with angiotensin II receptor blockers (ARBs), was associated with lower relapse risk 2 . Objectives To determine whether angiotensin blockade, with angiotensin converting enzyme inhibitor (ACEi) or ARB, is associated with differential relapse risk in GCA. Methods GCA patients from a tertiary centre diagnosed 2012–2020 with two years follow-up were identified from UK GCA Consortium. All provided written informed consent. Retrospective review of medical records included demographics, comorbidities, drug history, inflammatory markers and relapses. Relapse was defined as return of symptoms, raised inflammatory markers, or active vasculitis on imaging confirmed by the treating clinician. Relapse-free survival was analysed using Kaplan Meier (KM) curves and Cox proportional hazards. Results 111 patients were included (Table 1: demographic data), all were initially treated with 40–60mg Prednisolone. 42% received further immunosuppressants due to relapse or disease severity. 50% patients relapsed in two years, presenting with cranial symptoms (72%), PMR-like symptoms (30%) and/or raised inflammatory markers (48%). There was no association between relapse and age, gender, comorbid HTN/IHD or pre-steroid inflammatory markers and relapse. Rate of steroid taper can affect relapse. EULAR recommend 15–20mg of steroid by three months 3 . 9 patients relapsed within that time and were excluded, there was no difference in steriod dose at three months between the two groups. KM analysis showed ACEi did not significantly affect time to relapse compared to no angiotensin blockade (HR 0.57, 95% CI 0.28 – 1.18, unadjusted p-value=0.128), and neither did an ARB (HR 0.78, 95% CI 0.31 – 1.98, unadjusted p-value=0.605). Table 1. demographic data at baseline. Relapse (n = 56) No Relapse (n = 55) Patient Factors Age median (IQR ) 70 (65-74) 73 (67-78) Male Sex n (% ) 16 (29) 20 (36.36) Medications n (% ) ACEi 9 (15) 16 (29) ARB 7 (12) 7 (13) Comorbidities n (% ) CKD 4 (7) 9 (16) IHD 6 (11) 5 (9) Prediabetes 11 (20) 10 (18) DM 1 (2) 5 (9) HTN 22 (40) 23 (42) Current Smoker 6 (10) 2 (4) GCA Factors median (IQR ) CRP pre-treatment 69 (32 – 131) 64 (23 -115) ESR pre-treatment 50 (37 -95) 4 (22 -72) Steroid dose at 3 months 19 (15 -20) 15 (10-20) Figure 1. Unadjusted KM survival curve showing probability of relapse in patients 1) taking ACEi, 2) taking ARB, 3) taking neither ACEi or ARB, 4) with no comorbid HTN or IHD at diagnosis, and 5) experienced comorbid HTN/IHD. There was no significant difference in relapse free survival in patients on an ACEi compared to those taking neither ACEi or ARB. Conclusion In the two years following GCA diagnosis 50% relapsed. There was no significant difference in the rate of relapse in patients taking an ACEi or ARB. The main limitation, in this retrospective, observational study was the inability to exclude a reluctance of clinicians to diagnose GCA relapse in the presence of cardiovascular comorbidity. A randomised controlled trial would be needed to determine whether starting an ACEi could reduce relapse risk in patients with new-onset GCA. References [1]Mainbourg, S. et al. Prevalence of Giant Cell Arteritis Relapse in Patients Treated With Glucocorticoids: A Meta-Analysis. Arthritis Care Res. 72 , 838–849 (2020). [2]Alba, M. A. et al. Treatment with angiotensin II receptor blockers is associated with prolonged relapse-free survival, lower relapse rate, and corticosteroid-sparing effect in patients with giant cell arteritis. Semin. Arthritis Rheum. 43 , 772–777 (2014). [3]Hellmich, B. et al. 2018 Update of the EULAR recommendations for the management of large vessel vasculitis. Ann Rheum Dis 79 , 19–30 (2020). Disclosure of Interests Ranjana Venkateswaran: None declared, Karan Gour: None declared, Louise Sorensen: None declared, Charlotte Harden: None declared, Sizheng Steven Zhao: None declared, Ann Morgan Speakers bureau: Roche/Chugai., Consultant of: GSK, Roche, Chugai, AstraZeneca, Regeneron, Sanofi, Vifor., Grant/research support from: Roche, Kiniksa Pharmaceuticals, Sarah Mackie Consultant of: Roche/Chugai, AbbVie, AstraZeneca, Sanofi, Pfizer., Grant/research support from: Attendance at ACR21 supported by Pfizer. Attendance at EULAR2019 supported by Roche.